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Diseases in the Home Vegetable Garden ID & Management. Kenny Seebold Department of Plant Pathology University of Kentucky. Environment. Pathogen. Time. Host. Managing Disease in Home Vegetable Gardens. Causal agent – the pathogen Favorable environment Susceptible host
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Diseases in the Home Vegetable GardenID & Management Kenny Seebold Department of Plant Pathology University of Kentucky
Environment Pathogen Time Host Managing Disease in Home Vegetable Gardens • Causal agent – the pathogen • Favorable environment • Susceptible host • Use an integrated approach that affects one or more of these elements…
Building an Integrated Disease Management Plan • Disease identification – proper diagnosis is a key factor in managing any disease. • Understand how the environment affects disease development in the garden. • Be familiar with all the tools available for disease management. Use these in combination for best effect…
Bean Brown Spot Blight Pseudomonas syringae
Bacterial Wilt of Cucurbits Erwinia tracheiphila Control of cucumber beetle is critical factor for management
Yellow Vine Decline of Cucurbtis Serratiamarcescens Control of squash bug is key to management
Black Rot of Crucifers Xanthomonas campestris pv. campestris
Bacterial SpeckPseudomonas syringaepv. tomato Can be confused with bacterial spot!!
Bacterial CankerClavibacter michigensis subsp. michiganensis Marginal leaf burn (firing)
Bacterial Canker Cankers on stem
Bacterial Canker Bird’s eye spots on fruit
Management of Bacterial Diseases in the Garden • Prevention is critical • Resistance – pepper only • Sanitation • Remove and destroy diseased plants • Sanitize tools, stakes, etc. • Don’t handle plants if foliage is wet • Control weeds • Use pathogen-free seeds and transplants • Hot-water treatment or bleach soak • Heirlooms particularly at risk… • If watering overhead, do so early; don’t over-water • Fixed copper + Maneb/Mancozeb(1.5-3 lb/A): 5– 7 day intervals
Damping-offPythium spp., Rhizoctonia solani Rhizoctonia Pythium • Management • Use treated seed • Plant into well-drained, warm soils • Keep soil within recommended limits for pH and fertility • Don’t exceed recommended seeding depth • Remove or incorporate crop residue Snap bean
Bean Anthracnose Glomerella lindemuthianum • Management • 2-3 year rotation • Use treated seed • Mulch to reduce soil / water splash • Remove or incorporate crop residue
Tomato Pumpkin Pumpkin Pumpkin Powdery MildewOidium spp.
Management of Powdery Mildew • Rotation will not help • Plant resistant cultivars • May not be available for some crops • Promote air movement (increase plant spacing) • Fungicides • Sulfur • Potassium bicarbonate
Management of Downy Mildew • Rotation will not help • Plant resistant cultivars • Cucumber primarily • Promote air movement (increase plant spacing) • Fungicides (preventive use or at 1st signs of disease) • EBDC • Chlorothalonil
Gummy Stem Blight(Black Rot)Didymella bryoniae Watermelon Cantaloupe Pumpkin Cucumber
Gummy Stem BlightManagement • Crop rotation / deep turning of crop residue • No acceptable resistance in cultivars of watermelon, pumpkin, or cantaloupe • Fungicides • Chlorothalonil • EBDC’s (Dithane DF, Maneb)
Fusarium WiltF. oxysporum f.sp. lycopersici • Management • Use resistant varieties • Rotate to non-host (4-6 years in infested fields) • Remove crop debris & destroy
Southern BlightSclerotium rolfsii Whole-plant wilting Sclerotia, mycelium, & stem canker • Management • Rotation / deep-turn soil • Increase plant spacing • Remove diseased plants & destroy • Remove organic debris around plants • Physical barriers
Physical barriers Southern blight of tomato
Early BlightAlternaria solani • Management • Rotation / deep-turn soil • Plant resistant varieties / disease-free seeds & plants • Mulch around plants to minimize splashing • Avoid overhead irrigation / water early in day • Remove crop residue and destroy between crops • Control weeds in garden • Fungicides (chlorothalonil / mancozeb / maneb)
Septoria Leaf Spot / BlightSeptoria lycopersici • Management • Rotation / deep-turn soil • Use disease-free seeds and transplants • Mulch around plants to minimize splashing • Avoid overhead irrigation / water early in day • Remove crop residue and destroy between crops • Control weeds in garden • Fungicides (chlorothalonil / mancozeb / maneb)
Anthracnose (Ripe Rot)Colletotrichum spp. • Management • Rotation / deep-turn soil • Use disease-free seeds & plants • Mulch around plants to minimize splashing • Avoid overhead irrigation / water early in day • Remove crop residue and destroy between crops • Control weeds in garden • Fungicides (before fruit ripen) - chlorothalonil
Photo: APS Tomato Walnut Wilt Juglone (toxic substance excreted from walnut tree roots)
Tomato Blossom End Rot (Ca deficiency)
Foliar symptoms Dieback symptoms Bean Yellow Mosaic BYMV
Cucurbits Watermelon Mosaic Virus 2 Fruit symptoms Foliar symptoms
Aphid-transmitted Plant early – before vector populations build Control weeds Reflective mulches? Trap crops Aphid-Transmitted Viruses
Tomato Spotted Wilt Virus • Transmitted by thripspersistently • Removing infected plants doesn’t help • Controlling insects doesn’t really help • Reflective mulches (mirror mulch) helps • Barriers around individual plants helps • Resistant varieties available (quality??)
Spraying Home Vegetables • As with other practices, don’t rely solely on chemicals to manage disease! • Timely applications are critical • Apply before symptoms appear OR at first signs • Maintain a regular schedule • Safety & protective clothing • Re-Entry Interval after spraying • Home gardens exempt from worker protection standards • Suggest that you stay out of sprayed areas for at least 12 hours and until pesticides are dry • Choices of active ingredient are limited…
Captan: broad-spectrum seed treatment (protectant Hi-Yield Captan 50%WP Chlorothalonil: broad-spectrum fungicide (protectant) Bonide Fung-onil Dragon Daconil 2787 Hi-Yield Home and Garden Fungicide Ortho Daconil 2787 Ortho Garden Disease Control Copper compounds*: bactericide / broad-spectrum fungicide (protectant) Acme Bordeaux Mixture Hi-Yield Bordeaux Mixture Bonide Dragoon Dust Dragon Copper Fungicide Hi-Yield Copper Fungicide Fungicides for Home Vegetable GardensConventional Products
Mancozeb / maneb: broad-spectrum fungicide (protectant) Bonide Mancozeb Flowable Dithane Hi-Yield Maneb Garden Fungicide Sulfur*: powdery mildew / miticide (protectant) Dusting sulfur (various brands) Wettable sulfur (various brands) Fungicides for Home Vegetable GardensConventional Products
Bacillus subtilis:broad-spectrum fungicide Serenade Garden Disease Control Bordeaux mixture Botanicals Fungastop: broad spectrum citrus/mint oil Garlic GP Vegetable and Garden spray Neem oil: broad spectrum fungicide / insecticide Garden Defense Multi-Purpose spray Garden Safe Fungicide3 Ferti-lome Rose, Flower, & Vegetable Spray Safer 3-in-1 Garden Spray Fungicides for Home Vegetable Gardens‘Soft’ Chemistries / Organic
Copper compounds Potassium bicarbonate: powdery mildew Bi-Carb Old Fashioned Fungicide EcoMate Armicarb “O” GreenCure Organic Fungicide Kaligreen Sulfur*: powdery mildew / miticide (protectant) Fungicides for Home Vegetable Gardens‘Soft’ Chemistries / Organic
Home Vegetable Garden Resources • County Extension Offices • ANR and Hort. Agents • Short Courses, demonstrations, Master Gardener programs • Publications • Video Tapes & DVDs • Soil Tests • Plant Disease Diagnostic Labs (Lex. & Princeton) • Disease, Insect, Weed ID and control • Web Resources • KY Pest News • http://www.uky.edu/Ag/kpn/kpnhome.htm • ID-128 (Home Vegetable Gardening in KY) • http://www.ca.uky.edu/agc/pubs/id/id128/id128.htm • Plant Pathology Dept. • http://www.ca.uky.edu/agcollege/plantpathology/index.html • Hort. Dept. • http://www.ukyu.edu/Ag/Horticulture • Garden Data • http://www.gardendata.org